1. Cut a large rectangular piece of tuna from the loin.
2. Sear it on four sides in a non-stick pan. Remove quickly so that it stays rare in the center. Let cool.
3. Cut the loin into 4 portions and set aside in the refrigerator.
4. Cut the fennel in half lengthwise and slice into thin ribbons on a mandolin. Set aside in ice.
5. Do the same with the cucumber.
6. Cut the asparagus lengthwise into thin strips.

Presentation

1. Arrange the tuna slices in a spiral using a ring mold.
2. Season with Thai sauce.
3. Dress the crunchy vegetables (fennel and cucumber) with sherry vinegar, olive oil, salt and pepper and place on top.
4. Garnish with salmon roe and asparagus slices.